Kaya Scodelario, 21, became a cult heroine to a generation of Skins fans as Effy Stonem. She had to learn to jog for new C4 thriller Southcliffe.

Your first scene in Southcliffe sees you running along a country road. Are you a keen runner? Not at all. I had to learn to jog because I run like a fish. All my friends found the thought of me running on screen hysterical because I do absolutely no exercise.

But you’re so slim… I’m lucky, I’ve got one of those fast metabolisms where I can eat whatever I want and I don’t put on weight. But I know that’s only when you’re young. It’ll probably hit me when I’m 30.

So what is Southcliffe about? There’s a shooting spree in a small town and it’s about the reactions to that. For me, it was really about grief and how we all react differently. It was personal to me because I lost my dad two years ago, so those feelings… that was something I wanted to explore more. In Southcliffe, it’s a question of how do you support each other at times like that? It’s about human connections: what’s the most important thing, the living or the dead?

That sounds like pretty dark territory. Was it harrowing to work on? I can honestly say it’s one of the happiest projects I’ve worked on. Sean Durkin, the director, is such a calm person. He puts a lot of trust in the actors and that’s when you produce your best work.

Who do you play in it? I’m Anna. It’s quite a small part but I found her really interesting because she’s had a difficult relationship with her mother. And there’s such a generation gap growing now.

But aren’t you really close to your mother? She brought you up on her own. We are but I feel a gap because of social media, Twitter and so on. The world is so different now. For example, my mum calls it Facebookee! I do feel that it pulls us apart a bit.

That could happen to you one day… I know. I can remember getting my first laptop but there are kids now who are totally born to it. They know which buttons to press from the day they are born.

Joe Dempsie, another graduate of the Skins stardom school, is in Southcliffe. Do you have any scenes with him? He’s a really good friend, so when we found out we were in it, we were really excited. But I don’t think we ever had a scene together in Skins and we don’t in this either. But it was great to hang out together.

Southcliffe has a great cast, with actors such as Rory Kinnear, Sean Harris and Shirley Henderson. Was that intimidating? It was one of the reasons I wanted to do the part. Every job I take I really want to learn something. I’m still learning on the job. To see how they prepare for their roles was really inspiring.

Speaking of learning on the job, you started on Skins when you were only 14. What was it like growing up in public? It didn’t feel that way at all. On Skins we had such strong friendships, it just felt like we were a group of mates. We never saw ourselves as anything special, we never pretended to be anyone different to who we were. So there was no sense of missing out on growing up.

Your Skins co-star Jack O’Connell was your first boyfriend. That could have got messy when you broke up… We have a really strong friendship now. I am glad it worked out that way. There was never a ‘no fraternising’ rule on Skins. Jack’s doing well and we give each other advice when we’re thinking over roles.

You’ve got two movies set for release (Emanuel And The Truth About Fishes and The Maze Runner). Is that how you see the future? I like movies because I’ve been getting leads and TV is more about ensemble casts. In Emanuel, I’m a character who fixates on a doll and it slips between fantasy and reality.

You recently came back to Effy for the final series of Skins. Any hesitation about revisiting her? A lot! She was such a special character to me. I’d been with her a long time so I didn’t want her to be in the same place in life. But the idea was that it would focus on her transition from girl to woman and that struck a chord.

You’ve been in videos for Plan B and Robbie Williams… Ben (Plan B) was a friend before Strickland Banks, so when he said he wanted a girl like me for his video, I was in. And I had to do Robbie’s video or my friends and family would have killed me.

Your mum’s Brazilian and you speak fluent Portuguese. Any ambitions to act in that language? Absolutely, yes. I’ve got a dream about doing a drama about my mum’s background in Brazil and the struggles she faced to make the life for me, for us. It would be set in Brazil and I’d play the young her.

What does she think of that? She’s fine with it but she wants script approval.